TOWSON, Md. -- Maryland has received a federal grant to help fight cell phone use in prisons.

The Maryland Department of Public Safety and Correctional Services announced a $2 million contract over three years with Columbia, Md.-based Tecore Networks to deploy technology known as managed access.

The system only allows calls on approved cell phones. Unlike cell phone jamming, it does not interfere with calls outside prison walls and does not violate federal law.

About half of the money for the contract is being paid for with federal funds. The state is paying for the other half.

In the last fiscal year, about 1,300 cell phones were found by prison staff before getting behind prison walls, but hundreds of cell phones still get into the hands of prisoners.